Effect of Hydrogenation on oil and Isomerization

Hydrogenation brings changes on physical and functional properties of fats and oil. it  raises the melting point and reduces the iodine value (IV) of triglycerides. Completely hydrogenated fats (IV<1) are solid and brittle at room temperature. An advantage of hydrogenation is that a wide range of physical properties can be achieved. Functional properties of hydrogenated fat can be determined by solid fat index (SFI) and nuclear magnetic resonance (NMR). The parameters describe the relative amount of solid fat and liquid oil at fixed temperature. NMR gives value according to atomic structure and molecular weight of the substances. Read more

Modification of Fats and Oil: Hydrogenation

Hydrogenation of vegetable oil refers to conversion of unsaturated liquid oil into saturated or partially saturated plastic fat by catalytic addition of hydrogen. Most widely used catalyst is nickel. The main purpose of hydrogenation of vegetable oil is

  1. To modify oil for application in wide range of food uses such as production of margarine, deep frying oil, shortening in biscuit etc.
  2. To extend shelf life of fat by improving oxidative stability by reducing unsaturation. Unsaturated fats and oils are very susceptible to spoilage called rancidity.

For successful hydrogenation, crude oil impurities like phosphorous and sulfur compounds, free fatty acids, and residual soap need to be removed before proceeding for hydrogenation. These impurities have poisoning effect on catalyst and reduce its activity. Canola and rapeseed oil are particularly notorious for high level of natural sulfur which can cause problem in hydrogenation. Read more